Let's roll up our sleeves and solve this. We have 823 and we're going to multiply it by 97, essentially adding 823 to itself 97 times.
Step 1: 0 + 823 = 823
Step 2: 823 + 823 = 1646
Step 3: 1646 + 823 = 2469
Step 4: 2469 + 823 = 3292
Step 5: 3292 + 823 = 4115
Step 6: 4115 + 823 = 4938
Step 7: 4938 + 823 = 5761
Step 8: 5761 + 823 = 6584
Step 9: 6584 + 823 = 7407
Step 10: 7407 + 823 = 8230
Step 11: 8230 + 823 = 9053
Step 12: 9053 + 823 = 9876
Step 13: 9876 + 823 = 10699
Step 14: 10699 + 823 = 11522
Step 15: 11522 + 823 = 12345
Step 16: 12345 + 823 = 13168
Step 17: 13168 + 823 = 13991
Step 18: 13991 + 823 = 14814
Step 19: 14814 + 823 = 15637
Step 20: 15637 + 823 = 16460
Step 21: 16460 + 823 = 17283
Step 22: 17283 + 823 = 18106
Step 23: 18106 + 823 = 18929
Step 24: 18929 + 823 = 19752
Step 25: 19752 + 823 = 20575
Step 26: 20575 + 823 = 21398
Step 27: 21398 + 823 = 22221
Step 28: 22221 + 823 = 23044
Step 29: 23044 + 823 = 23867
Step 30: 23867 + 823 = 24690
Step 31: 24690 + 823 = 25513
Step 32: 25513 + 823 = 26336
Step 33: 26336 + 823 = 27159
Step 34: 27159 + 823 = 27982
Step 35: 27982 + 823 = 28805
Step 36: 28805 + 823 = 29628
Step 37: 29628 + 823 = 30451
Step 38: 30451 + 823 = 31274
Step 39: 31274 + 823 = 32097
Step 40: 32097 + 823 = 32920
Step 41: 32920 + 823 = 33743
Step 42: 33743 + 823 = 34566
Step 43: 34566 + 823 = 35389
Step 44: 35389 + 823 = 36212
Step 45: 36212 + 823 = 37035
Step 46: 37035 + 823 = 37858
Step 47: 37858 + 823 = 38681
Step 48: 38681 + 823 = 39504
Step 49: 39504 + 823 = 40327
Step 50: 40327 + 823 = 41150
Step 51: 41150 + 823 = 41973
Step 52: 41973 + 823 = 42796
Step 53: 42796 + 823 = 43619
Step 54: 43619 + 823 = 44442
Step 55: 44442 + 823 = 45265
Step 56: 45265 + 823 = 46088
Step 57: 46088 + 823 = 46911
Step 58: 46911 + 823 = 47734
Step 59: 47734 + 823 = 48557
Step 60: 48557 + 823 = 49380
Step 61: 49380 + 823 = 50203
Step 62: 50203 + 823 = 51026
Step 63: 51026 + 823 = 51849
Step 64: 51849 + 823 = 52672
Step 65: 52672 + 823 = 53495
Step 66: 53495 + 823 = 54318
Step 67: 54318 + 823 = 55141
Step 68: 55141 + 823 = 55964
Step 69: 55964 + 823 = 56787
Step 70: 56787 + 823 = 57610
Step 71: 57610 + 823 = 58433
Step 72: 58433 + 823 = 59256
Step 73: 59256 + 823 = 60079
Step 74: 60079 + 823 = 60902
Step 75: 60902 + 823 = 61725
Step 76: 61725 + 823 = 62548
Step 77: 62548 + 823 = 63371
Step 78: 63371 + 823 = 64194
Step 79: 64194 + 823 = 65017
Step 80: 65017 + 823 = 65840
Step 81: 65840 + 823 = 66663
Step 82: 66663 + 823 = 67486
Step 83: 67486 + 823 = 68309
Step 84: 68309 + 823 = 69132
Step 85: 69132 + 823 = 69955
Step 86: 69955 + 823 = 70778
Step 87: 70778 + 823 = 71601
Step 88: 71601 + 823 = 72424
Step 89: 72424 + 823 = 73247
Step 90: 73247 + 823 = 74070
Step 91: 74070 + 823 = 74893
Step 92: 74893 + 823 = 75716
Step 93: 75716 + 823 = 76539
Step 94: 76539 + 823 = 77362
Step 95: 77362 + 823 = 78185
Step 96: 78185 + 823 = 79008
Step 97: 79008 + 823 = 79831

So, 823*97 = 79831